1. Field of the Invention
The present disclosure relates to visible light communication systems, and in particular, to a visible light communication system which allows pairing in wireless communication between an information terminal and an information presentation apparatus to be performed using visible light.
2. Description of the Related Art
A light communication (visible light communication) technique is currently available in which visible light emitted from an illumination device is modulated for data transmission and a receiver receives the visible light and decodes the data from the modulated visible light. Wireless communication requires a dedicated device. In contrast, visible light communication using illumination does not require a dedicated device because an illumination device, which is normally installed inside a building, serves two functions of illumination and communication. Accordingly, the visible light communication has advantages in that interior design can be given consideration, a range illuminated by visible light is visible, and communication can be established in a limited space or area. The visible light communication can be mainly used in, for example, location-based services provided inside buildings, where radio waves of the global positioning system (GPS) are unlikely to be provided, by causing each illumination device to emit location information as data.
In a space such as an office, a conference room, or a public facility, it may be desired that content in an information terminal held by a user is output to an information presentation apparatus (for example, a speaker, a television (TV), a projector, a printer, and an electronic whiteboard) located away from the user in the same space. In such a case, connection information of each information presentation apparatus in the wireless network, to which the information presentation apparatus is connected, is obtained, and the connection information (internet protocol (IP) address, service set identifier (SSID), and password in the case of wireless fidelity (Wi-Fi)) is input to the information terminal of the user for wireless network connection. Accordingly, pairing between the information terminal and the information presentation apparatus is performed in wireless communication, allowing the content in the information terminal to be transmitted to the information presentation apparatus for output or display. Additionally, the pairing allows the information terminal to remotely control the information apparatuses. In order to facilitate convenience, when communication is to be established between two apparatuses, the connection information of one of the apparatuses is desirably input to the other apparatus easily. The term “pairing” refers to a process in which apparatuses which communicate with each other in wireless communication register links to one another.
For example, Japanese Unexamined Patent Application Publication No. 2009-124581 (hereinafter, referred to as PTL 1) discloses a method of establishing a connection between apparatuses, by pairing a remote controller with a TV to be controlled by the remote controller.
According to the technique disclosed in PTL 1, in a wireless control apparatus including a TV and a remote controller which wirelessly controls the TV, the remote controller is turned on. The remote controller then outputs a connection request packet to the photodiode in the TV using an infrared light-emitting diode (LED) and simultaneously performs pairing in wireless communication. On the other hand, upon receipt of the light of the connection request packet, the TV performs pairing in wireless communication.